Hi!
I have recently gotten hold of an old theodolite (just for hobby use). I have used total stations, gnss and other digital instruments a lot, but the old analog stuff is a bit unknown to me.
The instrument in question is a Kern K1-S, with the optional DM-501 distance measuring unit(!).
I am trying to figure out how to make a reading of the angle measurements, for example in the attatched picture I can make out a vertical angle of 298,32 gon (grad) and a horisontal angle of 130,16 gon. But aren't you able to make a reading with a finer precision than that?
Also the bottom scale with the arrow pointing left is a bit puzzling to me, what do you do with that one?
It has been way too long since I've used a scale reading theodolite. To me, it looks like the middle and the bottom readings are the angle value turned to the right and to the left (269 and a bit plus 130 and a bit make up the full 400 circle).
As to a finer reading, I'm interested to know as well. I've never used an instrument set up for grads. If I'm converting correctly, you are getting a 30" reading which is somewhat typical of many theodolites I've used.
I agree with Jon on this. While I've never run an instrument reading in Gons, I believe he is correct. I have run a DKM2 (AE) and found it to have one of, if not the, best optics of any gun I ever had. The DM501 that I ran read only in meters, which is fine by me. I will forever remember 3.2808333 as conversion from meters to feet.
Andy
You can apparently buy a user manual for about $22 at https://www.wild-heerbrugg.shop/product_info.php?products_id=163
I did not look for the DM-501 manual but I'll bet Google can help you.... There also seem to be a lot of YouTube videos out there.
It has been too long since I read a theodolite scale to help you out today.
Happy hunting!
If you have good eyes (or magnify the picture) you should be able to estimate another digit to perhaps +/-0.002 gon or ~7 arc seconds, so that the actual instrument accuracy is the limiting factor, not your reading.
@andy-bruner After almost 20 years in the field I've never seen an instrument that uses degrees!
A big thank you for all replies!, now I understand how the theodolite is meant to be read. I just assumed that it would have included some vernier-type scale.
The next step is to get the DM 501 to work, but I need to renovate the battery with some new cells first.
@andy-bruner After almost 20 years in the field I've never seen an instrument that uses degrees!
A big thank you for all replies!, now I understand how the theodolite is meant to be read. I just assumed that it would have included some vernier-type scale.
The next step is to get the DM 501 to work, but I need to renovate the battery with some new cells first.
If my memory is correct, the DM501 uses a special retroreflector. It is not a round prism but is oblong in the vertical direction. I hope you have good luck in getting it to work.
Andy
I always used for US Survey Foot 3937/1200 or its reciprocal for meters to feet and vice versa.
With the deprecation of the US Survey foot this bit of memory, like too many others, becomes moot.
For those new to the topic, when dealing with SPC the difference (USSF v Intl Ft) makes a real difference.
Decades ago I worked with French engineers who would frequently tout the benefits of the “systeme centesimal” over the legacy sexagesimal system.
Good thing calculators came along…
